HIGH-RELIABILITY 1.3-MU-M INP-BASED UNCOOLED LASERS IN NONHERMETIC PACKAGES

We report the first uncooled nonhermetic 1.3-mu m InP-based communicat ion lasers that have reliability comparable to their hermetically pack aged counterparts for possible applications in fiber in the loop and c attle TV, The development of reliable nonhermetic semiconductor lasers would not only lead to the elimination of the costs specifically asso ciated with hermetic packaging but also lead the way for possible revo lutionary low-cost optoelectronic packaging technologies, We have used Fabry-Perot capped mesa buried-heterostructure (CMBH) uncooled lasers with both bulk and MQW active regions grown on n-type InP substrates by VPE and MOCVD, We find that the proper dielectric facet passivation is the key to obtain high reliability in a nonhermetic environment, T he passivation protects the laser from the ambient and maintains the p roper facet reflectivity to achieve desired laser characteristics. The SiO facet passivation formed by molecular beam deposition (MBD) has r esulted in lasers with lifetimes well in excess of the reliability goa l of 3,000 hours of operation at 85 degrees C/90% RH/30 mA aging condi tion, Based on extrapolations derived experimentally, we calculate a 1 5-year-average device hazard rate of <300 FIT's Cas against the desire d 1,500 FIT/s) for the combination of thermal- and humidity-induced de gradation at an ambient condition of 45 degrees C/50% RH, For comparis on, the average hazard rate at 45 OC and 15 years of service is approx imately 250 FIT's for hermetic lasers of similar construction, A compa rison of the thermal-only degradation (hermetic) to the thermal plus h umidity-induced degradation (nonhermetic) indicates that the reliabili ty of these nonhermetic lasers is controlled by thermal degradation on ly and not by moisture-induced degradation. In addition to device pass ivation for a nonhermetic environment, MBD-SiO maintains the optical, electrical, and mechanical properties needed for high-performance lase r systems.